Safety burner



July 7, 1931. J. H. GRAYSON SAFETY BURNER 2 Sheets-Sheet 1 Filed July 20. 1929 1 July 7, 1931. Y J. H. GRAYSON 1,813,048

SAFETY BURNER Filed July 20. 1929 2 Sheets-Sheet 2 Patented July 7, 1931 UNITED STATES.

PATENT OFFICE JOHN H. GRAYSON, OF LYNWOOD, CALIFORNIA, ASSIGNOR TO GRAYSON HEAT CON- 'IPRlOL, INC., OF LYNWOOD, CALIFORNIA, A CORPORATION OF CALIFORNIA SAFETY BURNER 4pp1icati0'n filed .fuly 20, 1929. Serial 'NO. 379,680.

This invention relates to an improved safety burner.

The principal object of my invention is to provide a quick-action type. of safety burner and one which does not involve nearly as much restriction in the line as the usual thermostatic safety valve otherwise employed, so that the trouble of excessive pressure drop is avoided. -According to my invention, the tube or mariifold to which the gas is normally supplied and which has the orifice jets, is provided with a valve seat at the inlet 'end and a poppet or disc type valve to cooperate therewith arranged-to be normally held open by means of a thermostat operatively connected with the valve stem suitably extended through the tube through one or more guides provided therein.- This arrangement makes for the desired quick action and minimum restriction to gas flow, and, consequently, mlmmum pressure I drop. More- :over, the arrangement is one which is adaptsv able to burners-for various gas appliances, such as automatic water heaters, radiant heaters, and gas fired furnaces.

The-invention isillustrated in the accompanying drawings, wherein Figure 1 is a central, vertical section through a safety burner made in accordance with my invention, this particular type of burner being suitable for an automatic water heater;

Fig. 2 is a plan view of Fig. 1, and

Fig. 3 is a view partly in .side elevation and partly in central, vertical section of .a radiant heater burner utilizing my invention.

Corresponding reference numerals are applied to the parts in the three views.

The safety burner of my invention, as indicated above, is applicable to water heaters, furnaces, and other gas appliances, Wherever a pilot light is used to ignite the gas when it is turned on intermittently under the control.

of thermostatic or electro-magnetic valves. The pilot light, as is well known, is apt to be extinguishedthrough one cause or another, and when that occurs, if no safety device were employed, the urning on of the gas to the main burner would slmply mean that much waste, but more important still, it

mean the increase of the pressure drop beyond a limit set for such gas appliances. By incorporating the safety feature in the burner itself, as taught by the present invention, I am enabled not only to keep the cost low enough to make the same suitable for use on domestic gas appliances but, more important still, am enabled to keep within the pressure drop limit.

Referring first to Figs. 1. and 2, the frame 5 of the burner makes connection at 6 with a gas supply pipe 7. nd has a tube or manifold 8 threading therein, as shown at 9, for communication with the supply pipe 7, whereby to deliver gas to the main burner 10. A pilot burner 11 is mounted in the frame 5 alongside the main burner so as to light the same when the gas is turned on for said burner, and has the gas supply tube 12 therefor leading therefrom to a point'in the gas supply line ahead of the main shut-oft cock or the thermostatic or electro-magnetic valve, as the case may be. The tube 8 has the upper end thereof threaded for reception of a burner head 13 provided.

with commingling chambers 14 and ports 15. The head is open at the lower end thereof for the intake of air through an annular passage 16 communicating with the commingling chambers 14. The tube 8 has a plurality of annularly arranged jet orifices 17 in line with the commingling chambers 14, and with this arrangement the gas issuing from the jets l't will draw inair through the annular passage 16 by an injector action, and the gas and air are thoroughly mixed in the chambers 14 before issuing from the ports 15. The latter are preferably in the form of rectangular slots, the area of each of which is slightly less than the cross-sectional area of the connningling chamber associated therewith. The air supply is arranged to be regulated by adjustment of a valve disk 18 threading on the tube 8 below the burner head. It is easily seen how the main burner 10 is ignited by the pilot burner 11.

'lhe-safety shut off, provided in accordance with my invention, is, incorporated in the tube or manifold 8 in such a way that the same constitutes a unitary assembly which may be easily applied to or removed from the burner, thus facilitating inspection and cleaning, besides making for the desired compactness, simplicity and economy'm construction and adaptability to various modifications. The lower end of the tube8 is made smooth to 1 provide a seat for a poppet or disc type valve 20 mounted on a stem 21. A slight shoulder is provided on the stem, and 'a compression spring 22 fitting about the end of the stem and retained by a 'nut 23, normally urges the valve toward said shoulder. The purpose of this is to permit additional movement of the stem 21 after the closing of the valve,'so that the thermostat is relieved of strain and the valve will be held tightly closed under the action of the spring. The valve also has a loose enough. fit on the stem to take its own seat. In that way there will be no danger of leak-'- age due to the valve failing to seat all around, and the necessity for very close machine work is avoided. The stem 21 has a close working fit in a center hole in a bushing 24 which suitably has a press fit is the upper end of the tube 8'to close the same. 1y enough in the bushing to prevent the escape of gas. A bimetallic thermostat 25 is fastened to the frame of the burner as by means of a screw 26, and extends directly over the pilot burner 11,as shown in Fig. 2, toward the upper end of the stem 21. The inner end thereof is suitably notched out to fit in an annular groove in a nut 27 adjustably threaded on the upper end of the stem 21. The element In bf. said thermostat, the one exposed to the pilot light, may beof invar, which, as is well known, is practicallyfree from expansion or contraction b heat or cold, although any other material 0 generally similar characteristics might be, employed, and the element 6 of said thermostat may be of brass or copper, which, as is well known, have relatively high co-eflicients of expansion. Because of this arrangement of the elements of the bimetallic thermostat, it will be evident that when the pilot light heats the thermostat, the same is bowed downwardly, and when the pilot light is extinguished and the thermostat is cold, the same straightens out substantially as shown or may even become bowed upwardly.

The operation of the safety burner is believed to be clear from the foregoing descrip- The stem fits close- 7 remote there will be no danger of asphyxiation or danger of an explosion. On the other hand, assuming that the pilot burner remains lit, the valve 20 is kept open wide enough by reason of the bowed condition of the thermo-'. stat 25 so that there is'no restriction to speak of imposed on the flow of the gas, and consequently no noticeable pressure drop because of the incorporating of this safety feature in the burner itself. The disposition of the thermostat 25 extending across the top of the burner 10 is also of advantage because when the burner is ignited, the thermostat is heated more so than by the pilot burner alone, and as a result, the thermostat is bowed even farther than otherwise and holds the valve 20 farther away from its seat, thereby further eliminating any danger of any noticeable pressure drop due to this safety feature. If, at any time, it is desired to remove the main burner for purposes of inspection or cleaning, it is a simple matter to unthread the tube 8 from the frame 5, the valve 20 being small enough to'pass through the opening 9. The nut 27 can be adjusted so as to advance or retard the closing of the valve in relation to the cooling of the thermostat in a manner believed to be evident. A very important advantage of the present burner is the fact that it requires only a very short time for the gas to be shut off in the event the pilot light is extinguished and an equally short time to light the burner just after the pilot burner has been lit. The best known safety device on the market requires from six to ten minutes after the lighting of the. pilot burner before the main burner will pass sufiicient gas to ignite; the burner of my invention requires less than thirty seconds. In the event the pilot light is extinguished and the main gas supply turned on, the valve 20' can be counted upon to close Within four minutes, as compared with eight to ten minutes, for the best known safety device now available on the market. It is believed to be evident that the burner is of ,a very simple and economical construction and of a thoroughly practical character.

In Fig. 3, l have shown how the invention may be applied to a radiant heater burner. In that case, I provide the safety shut off in the manifold 8, which has the jet orifices 17' discharging into the commingling chambers 14: of the burner 10'. The air is drawn in through openings 16' by an injector action.

' 24 mounted. in the other end of the manifold 8'. The pilot burner 11 in this case is dis- ..posed alongside the bimetallic thermostat tioned en 25, and the heating of this thermostat is arranged normally to'keep the valve 20 open, the thermostat being arranged when heated to be bowed to the right sufficiently to hold the valve unseated, and when cooled being arranged to either straighten out as shown or become bowed to the left to close the valve. The operation of the safety shut off in this 33.56 will obviously be substantially the same as in the other case, and the same advantages are derived.

It is believed the foregoing descriptionconveys a clear understanding of my invention. The appended claims have been drawn with a View to affording protection on the embodiments described, as well as on all legitimate modifications and adaptations, such as will no doubt suggest themselves to others skilled in this art as a result of this disclosure.

If claim:

1. The combination with a gas burner having a gas supply pipe leading thereto, of a tubular manifold forming a part of. the burner itself and having its one end normally communicating with the gas supply pipe, said manifold having gas jet orifices in a predetermined relation to the ports of the burner, a valve seat at the first men manifold through which the stem. projects. out of the manifold, a pilot burner adjacent the gas burner for lighting the same, and an elongated flexible thermostat suitably supported at one end and disposed in transverse relation to the projecting end of the valve stem and having the free end thereof connected with the latter to communicate movement thereto in the flexing thereof, said thermostat having a portion thereof intermediate its ends in proximity with the pilot burner so as to be heated thereby.

2.- The combination set forth in claim 1,

wherein the valve disc is slidably mounted onthe remote end of the'valve stem toward and away from a stop on the stem, the combina- .60

tion including a coiled compression spring fitting about the-stem behind the valve disc normally urging'the same toward the stop, and an abutment on the stem behind the spring, the said spring permitting the stem to be moved by the thermostat independently of said manifold remote fromv of the valve disc after the same is seated so as .to relieve the thermostat of strain and also permitting the valve to adjust itself slightly with reference to the stem to take its own seat.

.3. The combination with .a' gas burner 4 a valve seat provided at the lower end of said manifold, a disc type valve movable upwardly toward the seat to close off communication between the' manifold and the gas supply .pipe, astem extending lengthwise inside the manifold and substantially concentric therewith having the valve disc mountedon the lower end thereof, a guide at the upper end of the manifold through which the stem extends and projects from the top of the burner, a pilot burner alongside the gas burner for igniting the same, and an elongated flexible thermostat substantially horizontally disposed above the burners with its outer end suitably supported in a fixed relation to the burners and its movable inner end connected with the projecting end of said stem for operation thereof, said thermostat being disposed with its intermediate portion above and suffi-'- ciently in proximity with the pilot burner to beheated thereby, said thermostat being further heated by the gas burner by reason of its extending over the same for connection with the valve stem,'whereby to insure good opening of the valve in the normal operation of the burner.

4;. The combination set forth in claim 3 wherein the valve disc is slidably mounted on the lower end of the valve stem toward and away from a stop above the same, the com bination including a coiled compression spring fitting about the stem below the valve disc normally urging the same toward the the stop, and an abutment on the stem below. the spring, the said spring permitting the stem to be moved upwardly by the thermostat independently of the valve disc after the same is seated so as to relieve the-thermostat of strain and also permitting the valve to ad just itself slightly with reference to the stem to take its own seat.

5. The combination set forth in claim 3 wherein the projecting upper end of the stem is threaded, the combination including a thumb nut threaded on said projecting portion and therefore accessible for easy ad ustment from above the gas burner, said nutllt ner end of said thermostat, the adjustment of said nut serving to adjust the stem endwise in relation to the thermostat to bring the valve disc closer to orfarther from'the seat when it is in its'normal en position.

6. In a safety urner, the combination. with'a burner support, a gas burner proper arranged to be mounted on said support, a

gas supply pipe connected to the burner support for supplying gas to the burner, and a pilot burner mounted on the support adjacent'the other burner, of a vertically disposed tubular manifold forming a part of the first burner itself at the center thereof, said manifold being threaded at its lower end in an opening provided in said support for detachably mounting the same thereon for communication with the gas supply pipe, said manifold having gas jet orifices at its upper end in a predetermined relation to the ports of the burner, the lower end of said manifold having a valve seat thereon, a disc type valve movable upwardly toward said seat to close off communication between the manifold and the gas supply pipe, said valve being small enough in diameter to pass through the opening in the support whereby to permit removal 5 thereof from'the support with the manifold,

a valve stem extendingupwardly fromthe valve in the manifold through. a guide provided therefor at the upper end of said manifold whereby it projects from the top of the burner, and an elongated flexible thermostat fixed at its outer end to the support and-extending inwardly over thepilot burner and first burner and having a detachable connec t' n at the movable inner end thereof with he projecting end of the valve stem.

In wltness of the foregoing I afiix my sig-.

nature.

JOHN HI GRAYSUN. 

